Table 2.

Identification of PFHxS isomers based on the observed specific series of product ions produced from the molecular anion m/z 399.

Fragment ion series			Main product ions (m/z) observed
Series	Formulaa	Possible product ions (m/z)	A1b	A2	M2	A3		M3	A4	A5
			M1b									M4
9-Series	[CnF2n+1]−	69, 119, 169, 219, 269, 319		169, 319	169∗	169	219	319∗	319 [219, 269]c	219 [119, 169]c
0-Series	[CnF2nSO3]−	80, 130, 180, 230, 280, 330, 380	80∗	230	230	130, 80∗	180∗
1-Series	[CnF2n−1 SO3]−	111, 161, 211, 261				211	261	161
7-Series	[CnF2n−1O]−	47, 97, 147, 197				147	197
PFHxS isomer			n-		iso-	2m-	3m-	1m-	1, 1m-	3, 3m-

^a: n = 1, 2,…, 6. ^b: Identified by comparison with the commercially available n-PFHxS standard and its quantitative ion was m/z 80. ^c: Fragment ions that cannot be produced due to the position of the branched chain. ^∗: The specific product ions were chosen to quantify the corresponding isomers.